Reconstitutable dry products of the type mentioned above, have been known for many years. In terms of organoleptic properties, in particular taste, such products have satisfactory quality and differ only slightly from those of home-made soups or sauces which are prepared from fresh raw ingredients. However, preparations made from these known dry products generally have a smooth, homogeneous structure. This texture is frequently desirable since the chef, in preparing this kind of soup or sauce from fresh raw ingredients, intends to obtain a smooth, creamy consistency, which is essentially based upon the starch content.
Starches useful for this purpose include native starches, i.e., starches which have been isolated from the plant, are present in pure form and which require a heating step to gelatinize them. These "swelling starches" are therefore pre-gelatinized, cold-swelling starches and may be produced in different ways. The most common method used to produce cold swelling starch is the roll-drying process in which the starch is pre-gelatinized and dried on the roll simultaneously, or pre-gelatinized first in a separate step and then subjected to roll-drying.
In certain cases, however, when preparing home-made tomato sauce, apple sauce, apple compote or "potages", the chef wants to produce a pulpy texture or structure which is an essential organoleptic quality generally absent from soups or sauces prepared from dry products. Experts, aware of this problem, have tried to develop different dry products which, in combination with aqueous liquids, will produce juices, sauces, or soups with a pulpy structure resembling that of finely pureed fruits or vegetables, such as "tomato concassee". However, a completely satisfactory solution has not yet been found.
One attempt to solve this problem is to add to the non-starch components of this type of dry product a gelatinized, cross-linked and/or high-amylose powdered starch product, and to heat this mixture to at least 72.degree. C. to cause the starch particles to swell as disclosed in U.S. Pat. Nos. 3,443,964, 3,579,341 and 3,650,770. Another solution which produces a dry product for preparing tomato drinks is to subject an aqueous mixture of tomato solids and gelatinizable starch materials, having a starch to water ratio selected to allow for partial gelatinization of the starch grains, to a roll drying process, as taught in U.S. Pat. No. 4,031,266. This solution is only moderately successful, however.
The only satisfactory solution to this problem is based upon the use, as a component of the starch portion, of a so-called "starch sponge" in which the fruit or vegetable substance is impregnated or incorporated into the starch matrix during production of the sponge, as in German Pat. No. 2,938,596. Upon reconstitution with hot aqueous liquids, these dry products yield sauces, soups, juices or compotes having an excellent pulpy structure, thereby solving the texture problem. However, starch sponges have the following disadvantages:
(a) the production of the starch sponge is time-consuming and comparatively expensive; PA0 (b) the cooking stability of the starch sponge is limited in that, after prolonged cooking, it slowly changes back to a normal starch paste so that the initial pulpy texture gradually becomes weaker and eventually disappears, and PA0 (c) the reconstitution with cold aqueous liquids frequently is slow and incomplete. PA0 1. Leguminous pre-gelatinized starches have a neutral taste which is advantageous especially when they are combined with, for example, fruit substances which have a delicate and easily suppressed flavor. PA0 2. The fat content of leguminous starches is very low which ensures good storage stability. This low fat content also renders the addition of stabilizers, such as phosphates during roll-drying unnecessary. (The addition of such stabilizers would otherwise be required with high-lipid cereal starches or flours to prevent rancidity.) PA0 3. The use of leguminous pre-gelatinized starches resolves texturing problems found in the prior art. By using the instant process, it is possible to combine chemically cross-linked starches with limited swelling properties (U.S. Pat. Nos. 3,443,964 and 3,579,341), with additives such as microcrystalline cellulose. An additional advantage of the invention is that if additives, flours or other starches are desired for specific applications, no major process modifications would be required and the resulting product would be of high quality. PA0 4. Leguminous pre-gelatinized starches of the invention, and the dry food products based thereon, provide dramatic swelling properties in cold aqueous liquids. Thus, the starch product of the invention requires no heating, which would otherwise be required with starch sponges to rehydrate the starch product smoothly and rapidly. The leguminous pre-gelatinized starches of the invention thus exhibit the same swelling characteristics in cold water as ordinary pre-gelatinized starches and may also, of course, be reconstituted in hot aqueous liquids. PA0 5. The ability of the leguminous pre-gelatinized starches to develop a pulpy texture on rehydration is increased by a known conditioning step, which consists of heat treatment with the starch containing an appropriate water content. This heat treatment may advantageously be conducted subsequent to the roll-drying process, provided the roll-drying step is conducted with the same water content in the starch when the film is removed from the roll, as that required for the conditioning step. PA0 6. Using the leguminous starches of the invention, it is possible to obtain products with a uniform appearance even when high proportions of starches are used. Unlike most known processes, this invention provides for separate production of compound leguminous pre-gelatinized starches, especially by roll-drying the starch in combination with other food components, such as fruit or vegetable substances. Therefore, the products obtained from these starches can exhibit a uniform appearance, if that is desired. PA0 7. To obtain a pulpy structure, the leguminous pre-gelatinized starches need not contain higher than a 50% amylose content. According to the instant process as illustrated by the examples hereinbelow, an amylose content of 40% or less is sufficient to obtain the desirable pulpy texture.
In conclusion, based upon the prior art, there appears to be a demand for a dry food product which can be reconstituted to form a pulpy textured fruit or vegetable juice, soup or sauce with cold swelling properties. Further, the product should remain stable upon exposure to prolonged heating conditions, such as in boiling, pasteurizing or sterilizing. It should also have the ability to be quickly reconstituted in cold or hot aqueous liquids. The process used to prepare this product should be cost effective. The present invention satisfies these requirements as described hereinbelow.